Field of the Invention
Exemplary embodiments of the present invention relate to a rear-wheel drive apparatus of an eco-friendly vehicle, and more particularly, to a rear-wheel drive apparatus of an eco-friendly vehicle, which is capable of improving the longitudinal driving force and handling performance of a vehicle by independently driving both rear wheels of the vehicle using a plurality of drive motors.
Description of the Related Art
In order to change a conventional front-wheel-drive eco-friendly vehicle, such as an HEV (Hybrid Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), an EV (Electric Vehicle), or a hydrogen fuel cell vehicle, into a four-wheel drive vehicle, a drive device configured by a motor and a reducer is typically mounted to the rear axle of the front-wheel drive vehicle, thereby improving the driving force of the four-wheel drive vehicle and securing the stability of the vehicle on the road such as the snowy road.
A conventional rear-wheel drive device typically includes a drive motor driven at high voltage, a reducer for obtaining the final reduction gear ratio of a vehicle, and a clutch or a brake serving as a wet-type multi-disk friction material in order to remove the unnecessary torque resistance of the motor.
Korean Patent Laid-open Publication No. 10-2013-0005407 discloses a technique for driving four wheels of an eco-friendly vehicle using a single drive motor for driving rear wheels, a planetary gear train for decelerating the single drive motor, and a differential gear connected to the output shaft of the planetary gear train.
However, the configuration disclosed in the above Document may improve only the longitudinal driving forces of front and rear wheels as in a typical four-wheel drive vehicle.
Hence, the method of driving the rear wheels using the single drive motor may not control the handling performance of the vehicle in situations where it is necessary to separately control the driving forces of both rear wheels, for example it is necessary to rapidly change lanes while the vehicle is traveling.